Cooling system for locomotive engines and the like

ABSTRACT

A locomotive cooling system has radiators mounted above the normal coolant level during engine shutdown in the engine and water tank so as to drain the radiators when the engine stops, to avoid the possibility of freezing the water therein. An automatic pressure relief and overflow valve is provided which is open during engine shutdown to drain excess water from the cooling system so as to prevent the retaining of any coolant in the radiators. When the engine is operating, the valve is normally closed by engine lubricating oil pressure to permit normal pressure buildup in the engine cooling system. However, the valve opens to relieve excess pressure in the cooling system. Manual opening means are also provided to relieve system pressure during engine operation.

Waited Mates Detroit, Mich.

COOLING SYSTEM FOR LOCOMOTIVE ENGINES AND THE LIKE 6 Claims, 3 DrawingFigs.

U.S. Cl 165/51, l23/4l.l4, l23/4l.08, 165/7], 165/107, 137/87,25l/l4,25l/77 Int. Cl F0lp 11/02 Field of Search 165/ 7 l I07, 5l;l23/4l.l4,4l.08,4l.54; IDS/62A;

180/54 A; l37/87;251/l4. 63.4, 77

Primary Examiner-Albert W. Davis, Jr. Attorneys-J. L. Carpenter andRobert J. Outland ABSTRACT: A locomotive cooling system has radiatorsmounted above the normal coolant level during engine shutdown in theengine and water tank so as to drain the radiators when the enginestops, to avoid the possibility of freezing the water therein. Anautomatic pressure relief and overflow valve is provided which is openduring engine shutdown to drain excess water from the cooling system soas to prevent the retaining of any coolant in the radiators. When theengine is operating, the valve is normally closed by engine lubricatingoil pressure to permit normal pressure buildup in the engine coolingsystem. However, the valve opens to relieve excess pressure in thecooling system. Manual opening means are also provided to relieve systempressure during engine operation.

PATENIEDuuv 23 ISYI sum 1. OF 2 COOLING SYSTEM FOR LOCOMOTIVE ENGINESAND THE LIKE FIELD OF THE INVENTION This invention relates to enginecooling systems for locomotives and the like and, more particularly, toan improved cooling system having automatic pressure relief and shutdownlevel control features.

DESCRIPTION OF THE PRIOR ART It is known in the art relating to diesellocomotives, power units and other mechanisms utilizing internalcombustion engines for exterior use, to provide a water cooling systemhaving radiators mounted above the normal water level in the system whenthe engine is shut down. This permits the water coolant to drain fromthe radiators during engine shutdown to avoid the possibility of coolantfreezing in the radiator elements, which are generally mounted in aposition exposed to air at ambient temperatures.

In such systems, it is normally possible to add cooling water to thetank while the engine is operating, at which time the level in the watertank is lower than when the engine is stopped and the cooling systemmay, therefore, be inadvertently overfilled. Then when the engine isstopped the water level may be sufficiently high to retain some coolantin the radiators with consequent danger of freezing in cold weather. Theproblem has been complicated by the recent use of pressure coolingsystems, which require relief of the system pressure in order to drainexcessive water from the system or to add water or cooling watertreatment to the water tank.

SUMMARY OF THE INVENTION The present invention provides an improvedengine cooling system of the above-described type which incorporates anautomatic valve having several functions. (1) It opens to relieveexcessive pressure in the cooling system. (2) It is normally closed whenthe engine is running so as to permit normal pressure buildup in thecooling system but it opens when the engine is stopped so as to drainany excess water from the cooling system and thus provide for positivedraining of the radiators. (3) It provides for manual pressure relief soas to permit safe removal of the water tank filler cap for filling ofthe water tank or the addition of water treatment.

Further details and advantages of the cooling system and valvearrangement will be apparent from the following description of apreferred embodiment taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

F IG. 1 is a side view representing, in part diagrammatically, alocomotive engine with attached cooling and lubricating oil systemelements;

FIG. 2 is an enlarged view of a portion of FIG. 1 taken generally in theplane indicated by the line 2-2 as viewed in the direction of thearrows; and

FIG. 3 is a cross-sectional view showing the interior construction ofthe valve as viewed in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, numeralgenerally indicates the car body of a locomotive in which there ismounted a diesel engine 12 having externally connected radiators 14(shown diagrammatically) and various lubricating and cooling systemelements mounted in a separate plumbing rack 16.

Engine 12 is of a type in current use for diesel locomotives andincludes a pair of water pumps 18 (only one being shown) which haveoutlets connecting with the internal cooling passages (not shown) of theengine. The engine also has a lubricating oil pump 20 which suppliespressure to the engine lubricating oil system whenever the engine isrunning. A pressure line 22 connects a distant portion of thelubricating oil system with the engine governor 24 to provide a pressuresignal indicating proper operation of the engine.

The engine cooling system passages have an outlet which connects throughconduit 26 with the radiators 14. The radiators are, in turn, connectedthrough conduits 28 with an oil cooler 30 mounted in the plumbing rack16. Oil cooler 30 then connects through dual conduits 32 with the inletsof the water pumps, completing the main cooling water flow circuit.

A water tank 34 is also mounted in plumbing rack 16 below the level ofthe radiators and is connected through vertical conduits 36, whichextend from the lower surface of the tank to the conduits 32 whichconvey water to the water pump inlets. The water tank is adapted toretain a supply of water and to provide a pressure head on the pumpinlets so that water is provided to the pump inlets under all operatingconditions.

When the engine is stopped, the cooling water level in the enginecooling system normally extends along a plane 38 slightly below the topof the water tank 34 so that no water remains in the radiators 14. Whenthe engine is running the water level in tank 34 drops, since the enginewater pumps maintain a solid flow of water through the main coolantcircuit and the water to fill the radiators is supplied by the watertank.

Water tank 34 is provided with an overflow pipe 40 which extendsinwardly to the normal shutdown water level and connects outwardlythrough an elbow 42 with an automatic pressure relief and level controlvalve 44. Valve 44 is, in turn, connected with a water drain line 46and, through oil lines 48 and 50, with the oil pressure line 22.

Valve 44 comprises a housing having a valve seat 52 which is engageableby a reciprocable valve element 54 to close the drain passage from thetank. Element 54 is supported by a movable guide member 56, whichcarries a spring 58. The spring acts against the guide member and aspring seat 60 so as to bias the valve element 54 toward the valve seat52. Travel of the spring 58 is limited when the valve is open by a capmember 62 that is attached to the guide member 56.

A hydraulic piston 64 acting within a cylinder 66 at one end of thevalve member connects with guide member 56 and is acted upon by a secondspring 68 which urges the piston in a direction to open valve element 54by moving the guide member, cap and valve element assembly 56, 62, 54.Provision is made for the introduction of lubricating oil pressure fromoil line 50 through an elbow 70 and orifice 72 to the interior ofcylinder 66 so as to act against the piston 64. Thus, when the engine isrunning, the oil pressure forces piston 64 in a valve closing directionso as to compress the spring 68 and permit the valve element 54 to beclosed by spring 58.

The valve 44 also includes a manual operating handle 74 connected with apivotable fork 76. The fork is engageable with a flange 78 of the valveelement 54 so that rotation of the handle 74 (in a clockwise directionas shown in FIGS. 1 and 2) is effective to manually open the valve bymoving element 54 in a valve-opening direction.

The operation of the above described cooling arrangement is as follows.When the engine is stopped, water and water treatment may be added tothe cooling system through a suitable opening (not shown) in the top ofthe water tank which is normally sealed by a suitable closure. When theproper coolant level is reached, the excess coolant flows into pipe 40and down through the open valve 44, passing out through drain pipe 46.Since there is no pressure in the engine lubricating oil system at thistime, spring 68 holds piston 64 in a leftward position, as shown in FIG.3, thereby moving the guide member and valve assembly leftwardly so thatthe valve is open.

When the engine is started, the lubricating oil pressure is transmittedthrough pressure lines 22, 48 and 50 to the cylinder 66 in the valvebody. There the oil pressure forces piston 64 to the right, permittingspring 58 to seat the valve element 54. At the same time, the enginewater pumps draw water from the water tank 34 and force it through theengine and into the radiators 14 from whence it passes through the oilcooler and around to the inlet of the water pumps in a continuouscircuit. As previously mentioned, the level in the water tank dropsduring engine operation due to the water taken from it, which is thenflowing through the radiators and other parts of the cooling system.

Operation of the engine increases the temperature of the coolant and,since the valve 44 is closed, pressure is developed in the coolingsystem, which permits operation of the system at high temperatureswithout boiling. If an excessive pressure is reached, the coolantpressure acting directly on valve member 54, moves the valve memberleftwardly against the bias of spring 58, opening the valve andrelieving the pressure. In this way, valve 44 acts as a pressure reliefvalve.

If, during engine operation, it is desired to add additional coolingwater or cooling water treatment to the cooling system, it is necessaryfirst to relieve the pressure in the system in order to permit thefiller cap closure to be safely opened. Such pressure relief may bemanually accomplished by rotating the valve operating handle 74clockwise, as shown in H68. 2 and 3, so that the fork member 76 engagesflange 78 of the valve member, moving the valve member in an openingdirection and relieving the cooling system pressure.

While the invention has been described by reference to a preferredembodiment selected for purposes of illustration, it should be obviousthat numerous modifications of the inventive concepts disclosed could bemade within the spirit and scope of the disclosure. Accordingly, theinvention is intended to be limited only by the language of thefollowing claims.

We claim:

1. An engine cooling system for a locomotive or the like, said coolingsystem comprising means defining coolant passages in such engine and acirculating pump having an outlet connected to supply coolant to saidpassages,

a radiator mounted at a high point in the cooling system, said radiatorbeing connected between the outlet of said engine coolant passages andthe inlet of said circulating pump to complete a closed circulationsystem,

a water tank mounted at a lower level than said radiator but above theinlet to said circulating pump, said tank being connected to said pumpinlet and being adapted to maintain a head of water coolant at said pumpinlet, and

a drain valve connecting with an upper portion of said water tank, saidvalve including means responsive to a predetermined condition of engineoperation to close the valve during engine operation so as to permit thecooling system to be pressurized and to open the valve when the engineis stopped to drain excess water in the system so as to maintain duringengine shutdown, a water level below the radiators to prevent anypossibility of the radiators being damaged due to freezing.

2. The cooling system of claim 1 wherein said drain valve isadditionally responsive to pressure in the cooling system so as to opento relieve any excessive pressure buildup in said system.

3. The combination of claim 2 wherein said drain valve further includesmanual actuating means to permit said valve to be manually opened duringengine operation so as to relieve the system pressure.

4. An engine cooling system having a coolant supply tank and a drainvalve connecting with an upper portion of said tank, said drain valvebeing responsive to a predetermined condition of engine operation toclose during engine operation so as to permit the cooling system tobecome pressurized and to open when the engine is stopped to drainexcess coolant from the system so as to maintain a predetermined maximumwater level during engine shutdown.

5. The cooling system of claim 4 wherein said drain valve is connectedto the engine lubricating oil system and is closed by the buildup ofpressure in said oil system during engine operation.

6. In a pressurized cooling water system of a diesel engine, thecombination with a storage tank and a radiator exposed to ambient airand connected to and positioned above the level of the tank for gravitydraining thereinto when the engine is stopped, of a dram port in a sideof the tank at a level at which the tank therebelow during running ofthe engine has sufficient excess water capacity to contain the thenwater content of the radiator, and an automatic dump valve connected tosaid dump port for automatically opening said port for and closing saidport against dumping respectively on stopping and running of saidengine.

1. An engine cooling system for a locomotive or the like, said cooling system comprising means defining coolant passages in such engine and a circulating pump having an outlet connected to supply coolant to said passages, a radiator mounted at a high point in the cooling system, said radiator being connected between the outlet of said engine coolant passages and the inlet of said circulating pump to complete a closed circulation system, a water tank mounted at a lower level than said radiator but above the inlet to said circulating pump, said tank being connected to said pump inlet and being adapted to maintain a head of water coolant at said pump inlet, and a drain valve connecting with an upper portion of said water tank, said valve including means responsive to a predetermined condition of engine operation to close the valve during engine operation so as to permit the cooling system to be pressurized and to open the valve when the engine is stopped to drain excess water in the systEm so as to maintain during engine shutdown, a water level below the radiators to prevent any possibility of the radiators being damaged due to freezing.
 2. The cooling system of claim 1 wherein said drain valve is additionally responsive to pressure in the cooling system so as to open to relieve any excessive pressure buildup in said system.
 3. The combination of claim 2 wherein said drain valve further includes manual actuating means to permit said valve to be manually opened during engine operation so as to relieve the system pressure.
 4. An engine cooling system having a coolant supply tank and a drain valve connecting with an upper portion of said tank, said drain valve being responsive to a predetermined condition of engine operation to close during engine operation so as to permit the cooling system to become pressurized and to open when the engine is stopped to drain excess coolant from the system so as to maintain a predetermined maximum water level during engine shutdown.
 5. The cooling system of claim 4 wherein said drain valve is connected to the engine lubricating oil system and is closed by the buildup of pressure in said oil system during engine operation.
 6. In a pressurized cooling water system of a diesel engine, the combination with a storage tank and a radiator exposed to ambient air and connected to and positioned above the level of the tank for gravity draining thereinto when the engine is stopped, of a drain port in a side of the tank at a level at which the tank therebelow during running of the engine has sufficient excess water capacity to contain the then water content of the radiator, and an automatic dump valve connected to said dump port for automatically opening said port for and closing said port against dumping respectively on stopping and running of said engine. 